Introduction

A family tree, or genealogy chart, traces a family’s lineage in a conventional node-link structure. It’s a chart that has been in use for millennia, across a range of cultures — perhaps one of the oldest forms of data visualization around. It puts into visual language the concept of ancestry and provides a kind of answer to the question of where we come from.

This project provides a cursory overview of how the family tree evolved over time, in both design and purpose. It highlights a few examples throughout history to compare and contrast. It also provides a report on current usage of the chart, and offers some ideas behind its constant popularity over centuries.

Methods

The timeline is an easy way to visualize the evolution of a design, capturing instances of it throughout history. Timeline JS, an open-source tool by the Knight Lab, allows anyone to create simple timelines by populating a spreadsheet with events and their corresponding years.

I first gathered data from various sources. Several museums and archives have objects in their collections that depict family trees, such as The Metropolitan Museum of Art, the Westchester County Historical Society, and The Walters Art Museum. I also reviewed various online articles whose authors have already researched the topic extensively, including on Atlas Obscura and the Nightingale blog on Medium.

Once I gathered enough examples, I curated the list down so that they reflected different eras in history and different design aesthetics. I tried to represent different cultures as well, although I only found one example from the Ottoman Empire. The oldest family tree in existence is often attributed to that of Confucius, the Chinese philosopher. In 2009, the chart was updated and released, spanning 80 volumes, covering 83 generations and two million descendants. However, I wasn’t able to find any visual documentation of this chart online.

Results

Looking at the Timeline, it’s clear that the node-link structure has remained largely the same over centuries (and millennia, although the earliest example in my Timeline only dates to 1480). The format is usually read from bottom to top, tracing generations of ancestors (the “tree branches”) from a single figure, typically placed at the bottom of the chart (the “tree trunk”). Each node, starting from the bottom, splits into a pair of other nodes (indicating marriage), and each of those nodes branch off into additional pairs, and so on.

Some versions of the chart collapse the paired nodes (marriages) into a single node, such as the Philipse-Robinson example. In this case, it’s less immediately obvious where the connections are between offspring and parents, but the efficient design allows room to fit more members of the family into a single diagram.

While structurally the family tree has remained intact, there are stylistic differences that can be identified over time. Aesthetic choices ultimately reflect the goals of the chart; the family tree’s style and content differ based on the context in which it’s used. Family trees of royalty are ornate works of art, as are the visualizations of Biblical figures seen in Renaissance art. These charts also tend to be smaller in scope, with figures carefully selected, as they are meant to be works for public display, not mere objects of documentation. In this context, family trees afford power and social status, connecting the past to the present for political purposes.

With the advent of cultural anthropology as a field of study, researchers began to use the family tree for purposes other than personal documentation. In Margaret Mead’s work on a community in Papua New Guinea, the lineage chart is pared down stylistically to show only connections and gender. Dotted lines are used to show groupings across generations that are relevant to her report. By abstracting out the family tree, these groupings are more easily identifiable.

Family trees that are found in scrolls or documents tend to be larger in scope and convey more information, such as the genealogical scroll from the Ottomon Empire. This scroll uses size, color, and other design elements to indicate different positions of importance. It includes names and years of death, although it leaves out pictorial representations of the figures.

In modern times, the family tree hasn’t lost its popularity; in fact, with new tools such as ancestry.com and 23andMe, tracing one’s family roots has become a pastime for many. 23andMe’s chart is auto-generated from its database, providing another way to visualize a person’s DNA relatives in the system.

The largest family tree comes from Yaniv Erlich’s team at Columbia University, where they gathered data online to connect existing trees together. Establishing a tree at this scale, containing 13 million people going back 11 generations and 500 years, allowed them to probe for research questions: they’ve identified and analyzed trends related to marriage and death.

Reflections

The tree metaphor has been used to describe lineage for millennia, since it was mentioned in the Bible, in the Book of Isaiah: “And there shall come forth a rod out of the stem of Jesse, and a branch shall grow out of his roots.” The concept of nodes branching off from a central “trunk” is an easy visual to grasp and provides a quick understanding of how ancestral lines are organized by generation. Over time, creators of the chart have adapted and tweaked it to meet their unique needs, though the overall node-link structure has remained unchanged.

The pursuit of family history is universal; many of us have wondered at some point the line of ancestors that precede our parents and grandparents. It situates us in a long continuous line of culture and history, connecting us in concrete ways to the broader world. This project is only a short glimpse into the deep history of mapping family histories. A more in-depth investigation could reveal how nuanced design trends progressed over time, and a wider survey of examples could also cover cultures outside of European traditions.

Resources

• Chen, Angela (2018, March 1). What the world’s largest family tree tells us about marriage and death in the West. The Verge. (link)
• Kahn, Paul (2020, November 27). Drawing Cultural Position: Transmission of Power Among Ancestors and Descendants. Medium. (link)
• Pendle, George (2016, May 16). Over 3,000 Years of Humans Exaggerating Their Lineage on Family Trees. Atlas Obscura. (link)
• Saxena, Jaya (2019, February 3). Why You Should Dig Up Your Family’s History — and How to Do It. New York Times. (link)